The present invention relates to motor-vehicle rear view mirrors of the type comprising a supporting body and a reflective plate pivotally mounted to the supporting body and movable between a position of normal use and an anti-glare position.
The rear view mirror located inside the passenger compartment of the motor-vehicle is conventionally provided with a manual control lever for controlling movement of the reflective plate between its two above identified operative positions.
A solution is also known and has been used which makes use of an electro-chromic layer on the mirror which is automatically darkened when light sensor means located at the front and at the rear of the mirror detect a light from rear much greater than the light at the front, which means that a glare condition due to the following vehicles is occurring. However, this automatically controlled device is relatively complicated and costly.
Italian patent application T098A000766 filed on Sep. 10, 1998, still secret at the filing date of the present application, has proposed a rear view mirror of the type indicated at the beginning, characterized in that it comprises spring means interposed between the reflective plate and the supporting body tending to hold the reflective plate in said position of normal use, and actuating means for controlling movement of the reflective plate towards the anti-glare position, comprising at least one element made of a shape memory metal alloy, and means for supplying an electric current through this element, so as to heat the element and cause a change of phase thereof which causes the movement of the reflective plate from the position of normal use to the anti-glare position.
In a preferred embodiment of the previously proposed solution, the shape memory element is a wire having one end connected to the mirror supporting body and the other end connected to one end of a lever transmission, whose opposite end is operatively connected to the reflective plate.